Vulnerability · Published Sep 21, 2026 · Assigned by GitHub_M
CVE-2026-58272Sync-in Server has Username/Login Enumeration via Timing Side-Channel on POST /api/auth/login (incomplete fix of the prior timing-attack advisory)
Medium 5.3
In plain English
A medium-severity security flaw in server from Sync-in. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Sync-in Server is an open-source platform for file storage, sharing, collaboration, and syncing. Versions prior to 2.4.1 contain an observable timing discrepancy in the login endpoint because authentication attempts for nonexistent accounts return without performing the bcrypt comparison used for existing accounts. An unauthenticated attacker can measure response times to enumerate valid usernames or email addresses, facilitating credential-stuffing, password-spraying, and phishing attacks. Version 2.4.1 contains a patch.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @sync-in/server | 2.4.1 | GHSA-29hq-23m2-2j47 |
Affected products (as reported)
Weakness: CWE-208 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
References
- https://github.com/Sync-in/server/security/advisories/GHSA-29hq-23m2-2j47 x_refsource_CONFIRM